Question: If $|A|=2$, where $A$ is $2 \times 2$ matrix, find $|\operatorname{adj} A|$.
Solution:
For any square matrix $A$ of orde $r n,|\operatorname{adj} A|=|A|^{n-1}$.
Given : $|A|=2$
Here, order is 2 .
$\Rightarrow|\operatorname{adj} A|=|2|^{2-1}=2$
